Level: beginner

Possibility and impossibility

We use could to show that something is possible, but not certain:

They could come by car. (= Maybe they will come by car.)
They could be at home. (= Maybe they are at home.)

We use can to make general statements about what is possible:

It can be very cold here in winter. (= It is sometimes very cold here in winter.)
You can easily get lost in this town. (= People often get lost in this town.)

We use can't or cannot to say that something is impossible:

That can't be true.
You cannot be serious.

Level: intermediate

We use could have to make guesses about the past:

It's ten o'clock. They could have arrived by now.
Where are they? They could have got lost.

We use could to make general statements about the past:

It could be very cold there in winter. (= It was sometimes very cold there in winter.)
You could easily get lost in that town. (= People often got lost in that town.)

We use can't have or couldn't have to say that a past event was impossible:

They know the way here. They can't have got lost!
If Jones was at work until six, he couldn't have done the murder.


Level: beginner

We use can and can't to talk about someone's skill or general abilities:

She can speak several languages.
He can swim like a fish.
They can't dance very well.

We use can and can't to talk about the ability to do something at a specific time in the present or future:

I can see you.
Help! I can't breathe.

We use could and couldn't to talk about the past:

She could speak several languages.
They couldn't dance very well.

Level: intermediate

We use could have to say that someone had the ability or opportunity to do something, but did not do it:

She could have learned Swahili, but she didn't want to.
I could have danced all night. [but I didn't]


Level: beginner

We use can to ask for permission to do something:

Can I ask a question, please?
Can we go home now?

could is more formal and polite than can:

Could I ask a question please?
Could we go home now?

We use can to give permission:

You can go home now.
You can borrow my pen if you like.

We use can to say that someone has permission to do something:

We can go out whenever we want.
Students can travel for free.

We use can't to refuse permission or say that someone does not have permission:

You can't go home yet.
Students can't travel for free.


We use could you … as a polite way of telling or asking someone to do something:

Could you take a message, please?
Could I have my bill, please?

can is less polite:

Can you take a message, please?


We use can I … to make offers:

Can I help you?
Can I do that for you?

We sometimes say I can ... or I could ... to make an offer:

I can do that for you if you like.
I could give you a lift to the station.


We use could to make suggestions:

We could meet at the weekend.
You could eat out tonight.

Questions and negatives

We make questions by putting the subject after can/could:

Can I ...?
Could I ...?
Can you ...?
Could you ...?


The negative form is can't in spoken English and cannot in written English.

We sometimes say cannot, but it is very emphatic.

The negative form of could is couldn't in spoken English and could not in written English.

can and could: possibility 1


can and could: possibility 2


can and could: other uses 1


can and could: other uses 2




Hello dharanikanth,

As is explained above,

We use could to show that something is possible in the future, but not certain.

That is the meaning in the sentence you ask about. You could replace 'could' with 'will' to, for example, make a prediction. See our talking about the future page for more on the different uses of 'will'.

All the best,
The LearnEnglish Team

thanks for the reply sir.

what is the difference between can & can be or could & could be?

You can easily lose your way in the dark or
You can be easily lose your way in the dark.

Hello mknm,

After 'can' we use a verb in the base form (the infinitive without 'to').

'Can be' is just the verb 'be' used after 'can'. It has no special meaning beyond this.

The sentence 'You can be easily lose your way...' is not correct. You would need to say 'You can easily lose your way...'


Best wishes,


The LearnEnglish Team

What is the difference between the following:

I can go for a movie.
I could go for a movie?

Hello neh7272,

The ways in which 'can' and 'could' are used are on this page. However, which are relevant in this example depends upon the context. You could be talking about ability or possibility, you could be making a suggestion, you could be making an offer - it is impossible to identify the intended meaning from the sentences without any context.

If you tell us what you want to say - the intended meaning - then we can tell you how you might do it.


Best wishes,


The LearnEnglish Team

Hello Mr.Kirk & Mr. Peter, I hope you are doing great.

I'm practicing English for few years but yet I've more doubts. I would like to know which of these correct and situational meanings about "What can I do for you?" & "What I can do for you" .. Please tell me which is correct and when to use it, I know more people using more often the second one in India alike "What will I do?" & "What I will do?" . Please reply the correct sentences.

Same doubt !

where are you ?

where you are ?

which is correct

Hello mknm,

If you want to ask the question then the first one is correct.


Best wishes,


The LearnEnglish Team

Hello sangeetha01,

If you intend to ask a question then 'What can I do for you?' and 'What will I do?' are the correct forms.


Best wishes,


The LearnEnglish Team